Fertiliser feeds us but trashes the climate – now there's a fix

Ammonia for fertilizer is usually produced at huge chemical plants like this one

Vsevolod Chuvanov/Alamy

By Andy Coghlan

Feeding billions of people around the globe takes a lot of energy. Much of the carbon cost of this effort comes down to making ammonia, the key ingredient in many fertilisers. To do this, we rely on the Haber-Bosch process, invented a century ago by German chemists Fritz Haber and Carl Bosch. No one has yet come up with anything that can compete with it on massive scales without breaking the bank.